Improve dashboard note view and add tests

Update the `#first_line_in_markdown` method so that the first line of
parsed text is displayed more reliably, and the continuation indicators
("...") are displayed in all cases where the note is truncated.

Also add Rspec tests for `EventsHelper#event_note`.

1 files changed, 25 insertions, 10 deletions

diff --git a/app/helpers/gitlab_markdown_helper.rb b/app/helpers/gitlab_markdown_helper.rb
index 27d8aee830c..7d3cb749829 100644
--- a/app/helpers/gitlab_markdown_helper.rb
+++ b/app/helpers/gitlab_markdown_helper.rb
@@ -56,16 +56,9 @@ module GitlabMarkdownHelper
   # +max_chars+ limit.  If the length limit falls within a tag's contents, then
   # the tag contents are truncated without removing the closing tag.
   def first_line_in_markdown(text, max_chars = nil)
-    line = text.split("\n").find do |i|
-      i.present? && markdown(i).present?
-    end
-
-    if line
-      md = markdown(line)
-      truncated = truncate_visible(md, max_chars || md.length)
-    end
+    md = markdown(text).strip
 
-    truncated
+    truncate_visible(md, max_chars || md.length) if md.present?
   end
 
   def render_wiki_content(wiki_page)
@@ -221,22 +214,44 @@ module GitlabMarkdownHelper
   def truncate_visible(text, max_chars)
     doc = Nokogiri::HTML.fragment(text)
     content_length = 0
+    truncated = false
 
     doc.traverse do |node|
       if node.text? || node.content.empty?
-        if content_length >= max_chars
+        if truncated
           node.remove
           next
         end
 
+        # Handle line breaks within a node
+        if node.content.strip.lines.length > 1
+          node.content = "#{node.content.lines.first.chomp}..."
+          truncated = true
+        end
+
         num_remaining = max_chars - content_length
         if node.content.length > num_remaining
           node.content = node.content.truncate(num_remaining)
+          truncated = true
         end
         content_length += node.content.length
       end
+
+      truncated = truncate_if_block(node, truncated)
     end
 
     doc.to_html
   end
+
+  # Used by #truncate_visible.  If +node+ is the first block element, and the
+  # text hasn't already been truncated, then append "..." to the node contents
+  # and return true.  Otherwise return false.
+  def truncate_if_block(node, truncated)
+    if node.element? && node.description.block? && !truncated
+      node.content = "#{node.content}..." if node.next_sibling
+      true
+    else
+      truncated
+    end
+  end
 end